Project Summary Aedes albopictus, is an aggressive human-biting mosquito and a competent vector of at least 22 arboviruses, including dengue, chikungunya, and Zika. Ae. albopictus represents a geographically extensive public health risk because of its ability to withstand cold temperatures which allow it to spread and establish from the native tropical regions to temperate localities. This ability to rapidly adapt to different temperature regimes represents a serious public health concern, especially in heavily populated urban areas of the U.S. where Ae. albopictus can occur at high densities. Lack of vaccines and drug treatments for most arboviruses makes vector control the most effective strategy for curbing disease spread. Our first goal in the proposed research is to develop a new powerful genetic tool for Ae. albopictus, a SNP chip to efficiently genotype tens of thousands of loci. This tool will address a longstanding knowledge gap due to the lack of high-resolution genetic markers for Ae. albopictus, and will be useful for a wide range of research topics from ecology to vector competence. In addition, a recent initiative by Verily Life Sciences (subsidiary of Google) to sequence 1000 Ae. albopictus will provide another rich source of data for our proposed work. In the current proposal we will: 1) Perform genetic surveys of worldwide field populations to reconstruct the species history and to allow rapid identification of the geographic origin(s) or current and future invasions (worldwide scale); 2) Understand the demographic parameters associated with range expansion on two previously identified and studied latitudinal transects from tropical to temperate areas in the native and invasive range (local scale); 3) Construct a publicly accessible standardized database of genetic variation of the species that can be used to trace future changes in this invasive species range; 4) Collect phenotypic data on diapause incidence from these samples and use the SNPs to identify genomic regions associated with diapause incidence to provide novel tools for vector control by disrupting this key trait linked to climatic adaptation. Results from this research will provide fundamental knowledge on the population dynamics of this important vector in its native and invasive habitats. The data will also provide practical information to help in the development and implementation of effective monitoring and control strategies.